Vatican police have arrested a Spanish prelate and a social media expert for allegedly stealing and leaking classified documents.

Vatican police have arrested a Spanish prelate and a social media expert for allegedly stealing and leaking classified documents.

Monsignor Lucio Angel Vallejo Balda, 54, who served on a special commission set up by Pope Francis to advise him on economic reform within the Vatican, was arrested along with a second member of the commission, Francesca Chaouqui.

The arrests were part of a several months-long investigation into the “misappropriation and disclosure of classified documents and information”.

They followed Italian media reports at the weekend that Vatican police were investigating the attempted theft of a laptop belonging to Libero Milone, the head of the city state’s new finance office.

Both Vallejo Balda and social media expert Chaouqui, 33, were arrested but Chaouqui was released by Vatican prosecutor Roberto Zannotti on Monday because she agreed to collaborate with investigators and was not considered a flight risk.

Chaouqui’s appointment to the economic commission, which was handpicked by the pope, caused no little embarrassment in 2013 when it emerged she had been highly critical of the Vatican on Twitter.

Vallejo Balda, who is currently languishing in a Vatican jail, belongs to a priestly society linked to conservative Catholic movement Opus Dei, which expressed “surprise and pain” at his arrest.

A furious Vatican also denounced the expected publication this week of two new books believed to be based on leaks from hackers releasing information regarding the famously murky world of its finances.

And it referred to the last time employees aired the centuries-old institution’s dirty laundry.

‘Defusing the bomb’

In 2012, Pope Benedict XVI’s butler engineered a series of leaks that revealed fierce infighting in the highest echelons of the Catholic Church and allegations of serious fraud in the running of the Vatican.

Butler Paolo Gabriele was sentenced to 18 months in prison for stealing secret papal memos but pardoned by Pope Benedict, who nonetheless banished his once loyal servant from the Vatican for good.

“As far as the books announced for the coming days go, it is clear that this time too, just as in the past, they are the fruit of a serious betrayal of the pope’s trust,” the Vatican statement said.

Italian journalist Emiliano Fittipaldi, who is releasing “Avarice: Documents Revealing Wealth, Scandals and Secrets of Francis’ Church”, writes for L’Espresso newsweekly, an avid publisher of leaks in recent years.

“Merchants in the Temple”, by Italian journalist Gianluigi Nuzzi, follows his 2012 book which was based on information gathered from Benedict’s butler in a scandal some believe was the reason behind the pontiff’s historic resignation.

Nuzzi is reported to be friends with Chaouqui, who hit the headlines again in 2014 when she was suspected of having organised a lavish party for the rich and famous on a Vatican terrace at the Holy See’s expense -- much to Francis’s fury.

The Vatican said it was considering taking legal action against the journalists.

Religious expert John Allen, writing for the Crux Now website, said that it was “a new proactive strategy for the Vatican”.

“Rather than waiting for the bomb to go off before trying to defuse it, this time the Vatican is trying to shift the conversation before the books even come out.

“How successful that strategy will be may depend on exactly what the books contain,” he said, adding that the Vatican had in any case “all but guaranteed these arrests will be a media sensation”.

Francis was tasked by his cardinal electors to stamp his authority on the bickering Curia, the Church’s governing body, and clean up the Vatican bank -- but the fresh leaks looked set to fuel criticisms of his reform programme.

His drive for transparency at the bank, once renowned for shady dealings, has ruffled feathers and supporters say the pontiff has been targeted by revengeful mudslingers -- including those behind a rumour last month, denied by the Vatican, that Francis has a benign brain tumour.